MECHANISM, ACTIVATION, & CONTROL OF RRNA TRANSCRIPTION

在大肠杆菌中，核糖体的合成主要控制在 RRNA转录启动。RRNA可占高达50%的 瞬时细胞RNA合成。为了更好地理解 蛋白质合成装置的生物合成，参与蛋白质合成的因素 RRNA合成的上游激活和生长速度依赖性调控 正在接受调查。RRNA启动子-RNA聚合酶的作用机制 目前正在使用动力学和足迹方法研究电离作用。这 将导致确定所涉及的各个步骤 RrnB P1启动子的转录启动及其影响因素 影响每一步。上游所需的特定DNA序列 激活和增长速度控制将由建设和 选择位点突变，然后分析操纵子在体内的融合。 最后，位置、方向和构象的重要性 上游激活序列(UAS)相对于启动子和 利用UAS增强异源基因转录的可行性 启动子也将通过体内操纵子融合进行检测。

In E. coli, the synthesis of ribosomes is controlled primarily at the stage of rRNA transcription initiation. rRNA can account for as much as 50% of instantaneous cellular RNa synthesis. In order to understand the biosynthesis of the protein synthetic apparatus, factors involved in the upstream activation and growth rate dependent regulation of rRNA synthesis are being investigated. The mechanism of rRNA promoter-RNa polymerase asociation is being studied using kinetic and footprinting methods. This will lead to the identification of the individual steps involved in transcription initiation at the rrnB P1 promoter and the factors that influence each step. The specific DNA sequences required for upstream activation and growth rate control will be defined by construction and selection of site mutations, followed by assay of operon fusions in vivo. Finally, the importance of position, orientation, and conformation of the upstream activator sequence (UAS) relative to the promoter and the feasibility of using the UAS to enhance transcription from heterologous promoters will also be examined using operon fusions in vivo.